Internal-combustion engine



N 1,618,859 0. s. CLARK INTERNAL COMBUSTION ENGINE Feb. 22 1927.

Filed, April 5.. 1925 2, She ets-Sheet 1 1,618,859 Feb. 22 1927. c. s. CLARK INTERNAL comsus'nou ENGINE Filed April 5. 1925 2 Sheets-Sheet 2 W Fit. 5-

(rwej/ahs C/an Patented Fee. 22, 1927. l

1,618,859 PATENT oFi-icizmarine STATES coannmuss. CLARK, on nonFoLK,,-vIneII\IIA, Assrenon 'ro CLARK ENGINEERING CORPORATION, or NORFOLK, vIneInIA,,a conrona'rron F VIRGINIA.

INTEnIIAL-ooM UsrIoN ENGINE.

This invention relates to internal combustion engines and proposes novel means for pron'ioting economy-and 'efliciency in the. op-

eration of such engines by controlling the v disposition of leakage fluids which ordinarily traverse the joint between cylinder-and piston under the urge of the differential crank case, the effect of which is to impairthe viscosity of the lubricant, and on the other hand, lubricating oil which is drawn upwardfrom the crank case into the 'combustion chamber, where it fouls the ignition terminals, and chars, forming a' carbondeposit upon the piston and wall of the cylinder head. 7

The present invention'is an improvement over the invention described and claimed in my Patent No. 1,540,602 grantedJune 2, 1925, in that it has for its object the provision, ofmeans employing gaseous fluid pressure applied to the joint between the cylinder and piston in a zone between the fuel entrapping means and the means for intercepting the lubricating oil; Another object of the invention is the provision of a manifold so constructed as to conveniently furnish both the sub and super atmosphericpressures required in the functioning of the device. q Other objects of the invention will be unfolded as the following description of apreferred embodiment thereof proceeds.

In the drawings Figure l is a side elevation of an internal combustion engine, parts being in section and parts broken away, showing the device of my invention applied thereto.

' Figure 2 is a vertical section through one of the pistons taken along 'the line 2-2 of Figure 1.

a-atr Figure 1. r p 7 Figure 4 is a section taken along the line 4+4 of Figure 1.

Figure 5 is a section of the lower'port io-n of the cylinder in a slightly modified form of the invention. 7

Figures 6 and 7 are fragmentary views taken respectively in cross and vertical section of the wrist-pin mounting of the piston.

Referring now in detail to the several fig- Figure 3 is a section taken along the line Application filedApriiS, 1925f SeriaI'N 20,569.

ures the numeral 1 represents a cylinderblock having, a. lower portion 2 which forms the upper half of the crank chamber. The

cylinders 3 are supplied with combustible mixture by means of an intake manifold 4.

and evacuated by an exhaust manifold 5,

said; manifolds being preferably cast inte grally' as shown so as to provide efficient heattransmission by conducting to the intake manifold, for the purpose of pre-' warming the combustible charge. Pistons 6 travel in. the cylinders 3. Broadly considered, the features above enumerated are old encept'that for the purpose of carrying out my invention, certain parts are modified in a manner presently to be'described.

As'has been stated in my application Serial No. 710 882. it is welljknown that a por I tion of the liquid fuel now available for use in internal combustion engines 1s d flicultly volatile at low engine temperatures so that it either remainsin liquid form or is con- Y densed into liquid after reaching the engine cylinders. Said liquid,'or a portion thereof is then forced down past the piston rings upon the compression and explosion strokes of the engine and finds its way into the crank case where it'commingles with the hibricating oil, ruii'iing the latter by impairing its viscosity. Not only isthe oil thus rendered. useless but the liquid fuel with which it is diluted, is wasted.

The present invention is similar to the invention described in my aforementioned application to the extent that the cylinder wall is provided with an upper annular channel 7 extending thereabout. said channel being located at such a zone in the cylinder as will be traversed by the intermediate portion of the piston body but never transsected by the piston ring or rings or the lower end of the piston skirt. 'Preferably'saidchannel is soarranged as to be an appreciable distance above the lower end of the piston when the latter is at 'the top of its stroke so as to be substantially sealed from Y communication with the crankcase. Said; channel is connected with a conduit 8 which'is one of the branches of a conduit 9, the latter com'-' Ill) ment of the intermediate portion of the pis- 7 to pressure from the exhaust manifold.

Upon the explosion of a charge of fuel mixture within a cylinder, the piston being then at the top of its stroke, a portion of the fuel is incidentally forced past the piston ring 15 into the narrow annular space be tween the piston and cylinder wall below said piston ring. invention, the most of this fuel becomes trapped in the channel 7 and is carried by suction directly into the intake manifold where it forms a proportion of the fuel being drawn into the cylinder. This salved fuel enriches the mixture to such an extent that the carbureter may be adjusted to supply a leaner mixture, an appreciable economy in fuel consumption being thereby effected. In my pending application aforementioned the suction in-the upper groove was relied upon solely for preventing the non-volatile fuel fraction from descending below the channel 7, but in this respect it was only in a measure efficient. By the present invention pressure is applied through the channel 11 to the space between the cylinder wall and piston, which supplements the action of the vacuum in the channel 7 and forces upwardly any portion of the leakage fuel which may have gottenpast said channel.

lVhen the piston descends upon its suction stroke, a high degree of vacuum is engendered within the combustion space Within the cylinder prior to the admission of a new charge of mixture, which vacuum causes the drawing up of a quantity of oil from those surfaces of the piston wall which have become wet with oil by splash from the crank case. Said. oil normally would mix with the leakage fuel as itis drawn oil from the channel 7, vitiating it by rendering it unfit for fuel consumption. In my pending application hereinbefore mentioned, provision was made for drawing this upwardly-flowing oil by suction, away from the space between the cylinder wall and piston, and then returning it to the crank case. By the present invention the same pressure which is employed to assist in preventing the descent: of fuel into the crank case is utilized in forcing back the film of oil which would otherwise encroach upon the descending fuel.

I have found it advantageous to provide a channel 16 below the channel 11, the former functioning as an interceptor for the ascending lubricant. A zone at superatmospheric pressure is therefore maintained In the operation of myv about the piston between the channels '7 and 16 which completely segregates the oil from the fuel, forcing each of said fluids back in the direction from which it emanated. The piston skirt is of such length as to expose the channel 16 to the crank chamber in the manner shown at 18 in Figure 1 every time the piston reaches the top of its stroke, the surplus lubricating oil being then blown out into the crank chamber by pressure from the channel 11 acting across the bridge 19. It may be desirable to have the interceptor 16 also in constant communication with the crank case. This may be accomplished by means of the passage 35, shown in Figure 2.

It is essential to the proper working of the system that the intermediate portion of the piston, that is to'say, that portion be tween the piston ring 15 and the lower end of the skirt be reasonably fluid-tight. For this purpose the wrist-pin bushing 20, illustrated in Figures 6 and 7 is made with a closed end and with a cylindrical curvature indicated at 21, conforming to the curvature of the cylinder wall. It has been found desirable also to employ a special ring for assisting in keeping the intermediate portion of the space between the piston and cylinder wall fluid-tight, which ring, in the present instance consists of a relatively broad member 22 surrounding a rib 23 formed in the ring groove of the piston, said member being flanked above and below by thin rings 24 and 25 which extend in a depth direction into shallow grooves at the sides of the rib 23. V

Although fluid-pressure from any suitable source may be utilized in the practice of my invention, I prefer to employ the exhaust pressure of the engine, and to the end that the present system of fuel and oil conservation may be applied to motors already in use, I have devised a novel form of manifold to be used as a replacement part for the ordinary intake and exhaust manifolds and which is so constructed as conveniently to supply the pressure for the channel 11 as well as the suction for the channel '1 Said manifold consists of an integral casting indicated, as previously stated, at 5 in Figure 1, the detailed construction of which is best shown in Figure 3, in which the intake pas sage 26 and the exhaust passages are pref erably formed in an integ al casting, the

walls of the former passage being warmed 1 wall of the intake passage is provided on manifold As it is necessary to deliver a certain pressure to thechannel l1 in order tohave the system functionproperly, means in the forrnof a valve 33 is provided in the exhaust manifold beyond the cylinders, for

creating a slight backpressurein said mani-,

fold. As a small degree of pressure is sufficient, the effect of the back pressure'upon the operation of the engine is negligible. The valve 33 may be adjustable so as to give more or less back pressure as conditions of operation of the engine 'may, demand.

In Figure 5 I'have shown a-form of the invention in which the interceptor 16 is made in the'form of a spiralgroove 34 extending to the bottom of the cylinder. This has the advantage of being constantlyin communication with the crank case, so that the surplus lubricant blown into the interceptor by pressure from the'channel 11 flows into the crank case continuously instead of at intervals as is suggested by the first described form of the invention.-

While I have'above shown and described what I believe to be a. practical embodiment of my invention, it is to be understood that the invention may be exemplified in numerous other constructions without transcending thescope of the invention.

Having described my invention what I claim as new and desire to secure by Letters Patent, is: 1. In an internal combustion engine, a cylinder including a combustion chamber,

and a crank case, a piston in said cylinder reciprocable relatively thereto and separating that portion of the cylinder wall ex posed to the combustion chamber from that part exposed to the crank case, one of said relatively reciprocable members being provided with means constantly overlain by the other for entrapping fuel leaking from the combustion chamber past said piston and with separate means for intercepting lubricating oil leaking past said piston from the crank case, and means for admitting fluid pressure to the space between said fuel trap and oil interceptor, for segregating said leaking fluids.

2. In an internal combustion engine, a cylinder including a piston chamber, and a crank case, a piston in said cylinder reciprocable relatively thereto and separating that portion of the cylinder wall exposed to the combustion chamber from that part exposed to the crank case, one of said relatively reciprocable members being provided with means constantly overlain by the other for entrapping fuel leaking from the combustion chamber past said piston and with separate means for intercepting lubricatingoil leakingv past said piston from the crank case, means foradmitting fluid pressure to the ,space between said fuel trap and'oil lnterc'eptor, for segregatlng S2L1Cl leaking fluids, and means operating through suction 'for'returning said entrapped fuel to the engine. I I

3. In an internal combustion engine, a cylinder-including a combustion chamber, anda'crank case,'a' piston insaid cylinder reciprocable relatively thereto and separating] that portion of' the I cylinder. iwall; 6X-- posedto the combustion chamber from that part exposed to the crankcase, one-of said; relatively reciprocable membersbeing provided with means constantly overlain by the otherfor entrapping fuelleaking from the combustion chamber past said piston, and with separate means for intercepting lubricating oilleaking past said piston from the crank case, meanscommunicating with the exhaust manifold of the engine for ad mitting fluid pressure to the space between said fuel trap and oil interceptor for segre' gating said fluids, and suction operated means communicating with said intake manifold for returning said entrapped fuel to the fuel mixture intake of the engine.

4. In an internal combustion engine, a cylinder including a combustion chamber, and a crank case, a piston in said cylinder reciprocable relatively thereto and separating that portion of the cylinder wall exposed to the combustion chamber from that part exposed to the crank case, said cylinder being provided with upper) and lower channels, said upper channel functioning to entrap fuel leaking from the combustion chamber past the piston, and said lower in a zone between said upper and lower channels and communicating with the exhaust manifold of the engine for admitting fluid pressure to said zone for segregating said fluids.

5. In an internal combustion engine, a cylinder including a combustion chamber, and a crank case, a piston in said cylinder reciprocable relatively thereto and separating that portion of the cylinder wall exposed to the combustion chamber from that part exposed to the crank case, said cylinder beingprovided with upper and lower annular channels extending transversely thereabout and with a channel in a one between said upper and lower channels, said upper channel functioning to'entrap fuel leaking from the combustion chamber past the piston, and said lower channel intercepting lubricating oil leaking past said piston from the crank case, a manifold for said engine having intake and exhaust passages, said upper channel being in communication with said intake passage whereby entrapped fuel is returned to said engine by suction and said intermediate channel being in communication with said exhaust passage for admitting fluid pressure to said zone for segregating said fluids.

6. In an internal combustion engine, a cylinder including a combustion chamber, and a crank case, a piston in said cylinder reciprocable relatively thereto and separating that portion of the cylinder wall exposed to the combustion chamber from that part exposed to the crank case, one of said relatively reciprocable members belng provided with means constantly overlain the other space between said piston and cylinder, be-

tween said fuel trap and crank case. 7

In testimony whereof I have hereunto set my hand.

' CORNELIUS s. CLARK. V 

